Running, swimming, cycling: ugh, they're all so much effort. Wouldn't it be just great if you could magically boost your motivation to exercise? Well, soon you might be able to, because scientists have discovered a compound that could do just that.

In a series of experiments in mice, a team of researchers from the Zurich Center for Integrative Human Physiology at the University of Zurich in Switzerland has found that erythropoietin (Epo)—a hormone present in small quantities in the human brain—makes the rodents more motivated to exercise.

The scientists took three kinds of mice: those that received no treatment, those that were injected with human Epo, and those that were genetically modified to produce human Epo in the brain. Compared to mice that didn't have Epo, both of the other groups exercised harder. The results are published in FASEB.

The researchers suggest that it should be possible to produce a similar effect in humans by increasing the concentration of Epo in the brain—though some form of pill or injection. What's more, that sounds entirely plausible, seeing as though it's a hormone that occurs naturally in the human body.

As with any study like this, though, you're not going to be knocking back exercise drugs just yet. But if the researchers can tie elevated Epo levels to a propensity to exercise in humans—say, in a population of athletes—then the waiting line for Epo pills is sure going to be a long one. [FASEB via EurekAlert]